German patent document DE 103 57 373 B4 discusses an electronic brake system for a vehicle having at least two brake circuits, which has a braking request recording device having two autonomous braking request recording means, one of which is connected to a central control unit while the other is connected to an autonomous brake circuit control system that is independent of the central electronic control unit. In the event of a failure of the central electronic control unit, the brake circuit control system in cooperation with the one braking request recording means assumes all activations of the vehicle brakes. The braking request recording means are sensors integrated into a brake pedal unit. This creates a certain redundancy.
German patent document DE 19815440 A1 refers to providing for a braking value sensor and a part of a control electronics of a vehicle brake system to be combined into one unit.